This invention relates to resistance bridge transducers, and in particular to conditioning circuits having means for calibrating of such devices.
Many transducers use a complete or partial Wheatstone bridge whose elements change resistance with the parameter (acceleration, pressure, structure strain, stress, etc.) being measured. The voltage change is normally small and must be amplified. The bridge must also be powered by a direct current. In many instances it is desirable for the bridge to have a known resistance inserted shuntwise with one arm to produce a calibration signal.
Improved operation of the system can be achieved if an analysis of the entire data collection system is provided by observing the system output calibration signal. Further advantage results from placing the signal conditioner close to the transducer thereby improving the signal to noise ratio of the resulting signal.
Present resistive bridge transducer signal conditioners however are too large to be conveniently placed at or in proximity to the transducer. Furthermore, conventional calibration circuits do not provide for analysis of the entire data collection system.
The present invention is directed toward overcoming these state-of-the-art circuit deficiencies by reducing the size and complexity of the conditioners and by providing a new and improved calibration circuit.